Question: Is there a
reason why my table salt is iodized? I’m
not even really sure what that means,
but it sounds a little scary, and
unnecessary. Should I switch to kosher
salt or sea salt?

Answer: Stick with the
iodized salt! It’s an important source
of iodine, a trace nutrient necessary
for proper thyroid function. Severe
iodine deficiency is rare in the US, but
about one third of women in the US have
low iodine levels, which makes them
especially susceptible to chemical
contaminants that interfere with thyroid
function.

One of these chemicals is
perchlorate, a component of rocket
fuel that has leaked out of military
sites and contaminated drinking water in
many states. It has also been found in a
variety of foods, including many produce
items and cow’s milk. The CDC has found
perchlorate in every one of almost 3,000
people who they tested, indicating
widespread exposure among the US
population. In addition, they also found
that in the one third of women with
lower iodine levels, exposure to
perchlorate at levels that are commonly
found in food and the environment was
associated with significant changes in
levels of thyroid hormone. This is
especially worrisome for women of
childbearing age because the developing
fetus is vulnerable to any decreases in
maternal thyroid hormone.

Iodized salt is no substitute for
aggressive public health protections
from thyroid toxins in the environment.
The government must step in and take
responsibility for cleaning up these
contaminants to levels that protect
human health.

In the meantime, as little as half a
teaspoon of iodized salt per day is
enough to maintain healthy iodine levels
in most people. People with medical
conditions like high blood pressure and
congestive heart failure should be
careful with their salt intake, and no
one should dramatically increase salt
intake without first checking with their
doctor.